BARCELONA (SPAIN)- Barcelona beaches were briefly shut down this week after lifeguards spotted three blue sharks close to the shore. Earlier this year Spanish fishermen caught a rare thresher shark off the Costa Brava. Are sharks rediscovering the Spanish mediterranean coast?

The sharks were spotted as close as two meters off shore, in the area where people were swimming. People were banned from the water after lifeguards spotted the small blue sharks, each between 1-1.5 metres long.The town halls in the popular resorts of Premia del Mar and El Masnou moved to close the beaches and raised red warning flags.

A surveillance boat was sent out to look for the fish but failed to find them. The beaches have since been reopened, with green flags indicating the waters are safe to enter.

The charity is still keeping two patrol boats out on the look out for the sharks.

The blue shark is a dangerous species which is known to have attacked other sharks and boats, according to the Florida Natural History Museum. It is hardly ever spotted close to shore.

Blue sharks outside a cage. Photo: Flickr Creative Commons/Kalanz.
Blue sharks outside a cage. Photo: Flickr Creative Commons/Kalanz.